It is common practice in building construction to provide electrical, telephone, plumbing and other service openings through barriers such as concrete floors, walls and ceilings, at the time the building is constructed and finished. While some of these openings may be used initially, others are reserved for future use. The barriers, being poured or cast concrete or the like, represent good fire barriers.
In some cases for a wide variety of reasons it may, also, be necessary at a later date to drill additional core holes for electrical, telephone or plumbing outlets in barrier floors, walls or ceilings. When outlets have to be moved, one is left with a hole which may typically be six inches deep and approximately three inches in diameter.
Such openings, cast or drilled, through an otherwise good fire barrier can reduce the integrity of the barriers and present potential fire and heat passageways. It is desirable to provide a closure fitting for each such opening, as such closures are needed, to thereby restore the integrity of the barrier.
Some solutions, such as currently available fire stops, leave an unsightly and dangerous metal plate exposed as well as being both individually and collectively costly.
A variety of other related technical solutions which have failed to totally successfully solve the problem in a commercially successful fashion will be touched upon in passing in the discussion of the known prior art provided below.